(Assuming you live in the Northland, where the humidity drops into one's
shoes time time of year....)
Hang a paper snowflake from the ceiling, using tape and a thread. (Or,
better yet, hang up several.)
Blow up a latex balloon (the old-fashioned rubbery kind, not a Mylar
one). Then, either using a reasonably clean head of hair or a natural
fiber sweater, charge up the balloon.
Bring it near the snowflake. The flake is strongly attracted, of
course. Typically one point heads straight for the balloon (or, anyway,
that's what I was seeing this evening).
Let the snowflake touch the balloon with one point. Let it stick
there. Hold the balloon still.
A few seconds later the flake pops off the balloon, and is repelled.
Chase it around a bit with the balloon, and notice that, repelled or
not, it continues to aim the same point at the balloon -- it rotates to
keep the same orientation relative to the balloon.
Now, most of this behavior is obvious, though fun, but there were a
couple questions I had some trouble answering.
1) The flake picks up a charge from the balloon ... obviously ... and
then is repelled. But why doesn't it happen _right_ _away_? What's
going on during the delay? The flake pops off all at once when it
finally leaves, and seems strongly repelled afterwards -- why doesn't it
come loose when it's just about neutral relative to the balloon? (The
flakes were cut from plain-paper copier paper, by the way. Sizes varied
from about 1.5" to perhaps 4".)
2) Last I heard, dry paper was a pretty bad conductor. The charge
draining off the balloon must be going into the point of the flake which
is touching the balloon. One would expect that point to end up with the
largest charge; then, the flake would spin around and turn the other
way. But that doesn't happen. Once the flake stops being attracted to
the balloon, the point which was _touching_ the balloon is the one which
remains pointing toward the balloon, even as the flake as a whole
skitters away. How come?
If you happen to be an LP afficionado, you can try this, too:
Stick a balloon or two or three to the ceiling with static.
Zap them with a Zerostat.
They go right on sticking -- they don't come loose! Why not? Why is
the Zerostat so bad at bleeding charge off a balloon? It used to work
like gangbusters getting dust off my LPs. This one appears to still
work; I can still feel the breeze from the nozzle when I work the
trigger. The room was starting to smell like ozone by the time I gave
up trying to shoot down a balloon from the ceiling with it.
************************
If you're really bored and are sick of discussing religion on Vortex, or
you need to entertain someone young, you can also put a well-charged
balloon or two on a tabletop and bring another charged balloon near
them. No surprises there but it's fun none the less...
